Fusion Energi 2018 forcing regen charge

[BL1999]

I am having an ongoing issue with my Fusion Energi SE 2018 forcing to charge with regen. Back in May of this year, I left my car charging for the entire day to find it completely dead upon trying to start it up. The only conclusion I could come up with is that a bad volt from the weather shocked the car and fried some components and the main battery. I ended up having to replace the battery since it looked like it went bad in that very instance which fixed the functionality of my car for the most part.

 

However, a symptom came up where the engine will not immediately go through regen and go off the gas which in most cases kill my MPG. I have to drive about half a mile before regen starts kicking in. If I leave my car without a battery charge throughout the day, it shows that the battery reserve is depleted entirely and it has to boot up the engine to compensate.

 

I approached a dealer to see their impression and they offered $150 to inspect the car over a period of time with the notion that the battery warranty will come in effect since my car is under 100k miles but I am skeptical of their policies and want to ask here before I decide to do it. I just want to know what part could've been damaged and if it can be covered with the warranty.

 

[jsamp]

To be honest I'm having difficulty understanding what you are talking about.  I'm not sure what you mean by "forcing to charge with regen".  If the car is cold and you start up the gas engine, two things will happen:  1) The gas engine will be in cold-start mode where the car will use the HV battery for propulsion for about 30 seconds (depending on temps it could be 1 minute) before revving up the gas engine.  and 2) it will NOT turn off the gas engine until it has completely warmed up, no matter what mode you subsequently set the car in (Auto, EV Now, EV Later).  Once warmed up (about 5 minutes, sometimes more), it will turn off the gas as the computer deems necessary based on the driving mode selected.

 

Did you replace the High Voltage Battery (for thousands of dollars) or the 12V battery?  Sometimes it seems you are talking about one and other times the other.  That day in May were both batteries completely dead, or just the HV battery?  If you truly had a voltage spike like from a lightning strike, it could have fried many components on many boards.  That could be ugly.

[BL1999]

On 7/11/2023 at 12:05 AM, jsamp said:

To be honest I'm having difficulty understanding what you are talking about.  I'm not sure what you mean by "forcing to charge with regen".  If the car is cold and you start up the gas engine, two things will happen:  1) The gas engine will be in cold-start mode where the car will use the HV battery for propulsion for about 30 seconds (depending on temps it could be 1 minute) before revving up the gas engine.  and 2) it will NOT turn off the gas engine until it has completely warmed up, no matter what mode you subsequently set the car in (Auto, EV Now, EV Later).  Once warmed up (about 5 minutes, sometimes more), it will turn off the gas as the computer deems necessary based on the driving mode selected.

 

Did you replace the High Voltage Battery (for thousands of dollars) or the 12V battery?  Sometimes it seems you are talking about one and other times the other.  That day in May were both batteries completely dead, or just the HV battery?  If you truly had a voltage spike like from a lightning strike, it could have fried many components on many boards.  That could be ugly.

I only had to replace the 12v battery which as previously mentioned made the vehicle perform normally aside from my car struggling to smoothly transition into hybrid mode. From what I could tell, the HV battery didn't appear to be affected by the event. I did drive the vehicle around with the old battery as I tested it with jumpstarting but it would die upon turning off the car and that's when I first noticed the particular issue with hybrid mode.

 

To add clarity, this would happen no matter how much excess power from hybrid mode is there, as if the car cannot detect the power properly until I drive about half a mile where it functions normally. So if I run out of HV battery and it comes to hybrid mode, it would normally be topped off in power but accelerating beyond a certain speed threshhold will make the car forced to run on gas even if I decelerate for some time. Some of the energy will still be allocated when I do approach higher speeds (around 40 mpg) but only if I go down say the Interstate road to reach those kinds of speeds, otherwise the engine ignores hybrid mode entirely.

Edited July 11, 2023 at 12:39 PM by BL1999
clarity

[jsamp]

Can't say I've heard of this ever before.  Not sure what the cause or solution might be.  Sorry.

[cr08]

On 7/11/2023 at 8:08 AM, BL1999 said:

To add clarity, this would happen no matter how much excess power from hybrid mode is there, as if the car cannot detect the power properly until I drive about half a mile where it functions normally. So if I run out of HV battery and it comes to hybrid mode, it would normally be topped off in power but accelerating beyond a certain speed threshhold will make the car forced to run on gas even if I decelerate for some time. Some of the energy will still be allocated when I do approach higher speeds (around 40 mpg) but only if I go down say the Interstate road to reach those kinds of speeds, otherwise the engine ignores hybrid mode entirely.

 

This still confuses me how you have it written but it feels like this is the ICE warmup cycle that @jsamp already covered. By chance when this process begins was the ICE cold/hasn't ran in a while or during that drive cycle?

 

Hopefully to give further clarification how the ICE 'cold start' procedure operates: When the ICE initially starts up cold, it'll essentially idle and not produce any propulsion unless you put in heavy amounts of throttle input. You can view the power split gauges on the dash and the lion's share will be on the EV side with a sliver of white for the ICE. The vehicle is moving mainly on electric power still at this time. And when stopped, it'll also put energy back in the battery while the ICE continues to warm up just to 'bleed off' some of that power. It isn't until the emissions system is happy (within the 30s-1m of warmup previously mentioned) that the car allows the ICE to help propel the vehicle and the power split will then show the ICE side doing most of the work.

[BL1999]

On 7/12/2023 at 7:34 AM, cr08 said:

 

This still confuses me how you have it written but it feels like this is the ICE warmup cycle that @jsamp already covered. By chance when this process begins was the ICE cold/hasn't ran in a while or during that drive cycle?

 

Hopefully to give further clarification how the ICE 'cold start' procedure operates: When the ICE initially starts up cold, it'll essentially idle and not produce any propulsion unless you put in heavy amounts of throttle input. You can view the power split gauges on the dash and the lion's share will be on the EV side with a sliver of white for the ICE. The vehicle is moving mainly on electric power still at this time. And when stopped, it'll also put energy back in the battery while the ICE continues to warm up just to 'bleed off' some of that power. It isn't until the emissions system is happy (within the 30s-1m of warmup previously mentioned) that the car allows the ICE to help propel the vehicle and the power split will then show the ICE side doing most of the work.

This happens during the driving cycle a multitude of times before hybrid mode starts to act properly. If I have to make a quick stop then I activate my car again, the same result will happen no matter how long I've been driving for throughout the day. I believe the propulsion stage of the car startup may have problems detecting the hybrid power reserve on the HV battery as it tends to start completely empty if I don't charge my car overnight. Before the incident, there was always a small amount left on the reserve and it would give me power upon braking at any point of time but now it acts like it has to force the charge itself when I'm driving before it starts to function normally.

Edited July 12, 2023 at 03:20 PM by BL1999

[theterminator93]

I would have the dealership do the diagnostics. If they determine the HVB or BECM are at fault, the diagnostic fee should be returned to you and the cost of parts and labor to repair will be covered under the "unique hybrid powertrain components" warranty.

[BL1999]

So I took the liberty of buying a scanner and it came up with two codes, U0253 and P0420. I assume the former is just a false flag and it's nothing to worry about but the latter may be the culprit of my issue at it notes poor fuel economy and a bad smell which somewhat occurs if I leave the AC running without any cooling. Of course I could be mistaken but it's a possible lead.